1. Field of the Invention
This invention relates to disassembleable core heat exchangers. More specifically, the invention relates to disassembleable core heat exchangers for construction machinery, vehicles, trucks or the like.
2. Information Disclosure Statement
The standard procedure recommended in carrying out repairs on the engines, transmissions, and hydraulic systems of earth moving equipment is to replace the oil cooler heat exchanger. The replacement of these heat exchangers ensures that no contaminants find their way into the relatively complex and expensive mechanisms. However, the average cost of a replacement heat exchanger is currently in the region of $900.00. This high cost of replacement greatly increases the overall cost of repairing or overhauling the transmission on tractors and other excavating equipment.
In an article in the periodical Caterpillar Engine News dated July 8, 1976 under the caption "Install New Oil Coolers After a Component Failure", reference is made to the needed replacement as follows: "The engine, transmission and hydraulic systems are equipped with oil coolers. Many times a failure in these systems can put debris into the lubrication or hydraulic oil. This debris is then sent to and held by the oil coolers at their specific locations. No method is known to clean or flush this debris from the oil coolers. If a new oil cooler or core is not installed when repairs are made, it is possible for the debris to work loose and get into the lubricational hydraulic system. Debris held in the oil cooler may decrease oil flow and increase oil temperature and cause other failure.
"Inspection of the damaged parts, oil pump, filters, suction screens and sumps will give a good indication of the amount of debris in the oil system. If indications show a large amount of debris, then a new oil cooler or core should be installed according to replacement specifications. It is not necessary to install a new oil cooler or core at every failure, but it is a must when inspection shows large amounts of debris in the oil system.
"The service life of a rebuilt engine, transmission or hydraulic system can be extended if a new oil cooler or core is installed when the rebuilt component is installed. If a new oil cooler or core is installed at the time of rebuilding, then debris from the previous failure cannot re-enter the lubrication system."
The present invention has as its primary objective the overcoming of this expensive replacement of heat exchangers for engines, transmissions and other hydraulic systems.
The disassembleable core heat exchanger of the present invention overcomes the aforementioned inadequacies of the prior art devices by providing a core that can be readily removed from the heat exchanger housing for cleaning and removal of debris therefrom and which is able to be reassembled without need of expensive replacement thereof.
Another object of the invention is the provision of a heat exchanger having an elongated housing and two cooperating end portions disposed at opposite ends of the housing and a removable core of tubes slidably disposed within the housing.
Another object of the invention is the provision of a pair of collars, each collar associated with a respective end portion, the collars being adjustably moveable relative each other to seal the core tubes relative the elongated housing.
Another object of the present invention is the provision of a plurality of threaded tie rod ends disposed between the collars for adjusting the relative disposition of the collars and associated end portions.
A further objective of the present invention is to provide a method of making a disassembleable heat exchanger which includes the steps of cutting through one end of the housing in the vicinity of the second tube retaining plate and cutting said second tube retaining plate circumferentially to separate the same from the housing, cutting transversely through the other end of the housing to permit one end portion and attached core tubes to be slid out of the housing, providing a ring around the periphery of the second tube retaining plate and replacing the core tubes within the housing.
Another object of the present invention is the provision of a method of making a disassembleable heat exchanger in which a gasket or seal is disposed between the end portion and the housing and a seal is provided around the ring to form a seal between the ring and the housing.
A further object of the present invention is the provision of a heat exchanger in which, in addition to the provision of a brazed ring disposed around the second tube retaining plate, the opposite end of the housing is transversely cut in the vicinity of the first tube retaining plate. The first tube retaining plate is then cut circumferentially to enable separation of the first tube retaining plate and the core tubes from the housing. A brass or copper flange having a central aperture corresponding with the diameter of the cut first tube retaining plate is slipped over the first tube retaining plate and brazed thereto. A gasket or seal is slipped over the core tubes and positioned to form a seal between the brass or copper flange and the housing on reassembly of the core tubes with the housing.
Another object of the present invention is the provision of a removable core cooler, the configuration of which makes possible the repair of the same.
Another object of the present invention is the provision of a method of repairing the effects of fretting corrosion partially due to vibration between the core tubes and supporting baffles.
Another object of the present invention is the provision of a replaceable core configuration which facilitates the replacement of a leaking core tube.
Another object of the present invention is the provision of a disassembleable core heat exchanger in which an O-ring is pressed into sealing engagement with an annular groove defined respectively by a counterbore, an annular shoulder, an annular ledge and a tube retaining plate for sealing the groove between the housing and the retaining plate.
Another object of the present invention is the provision of a method of converting a flangeless heat exchanger into a disassembleable core tube heat exchanger.
Another object of the present invention is the provision of a disassembleable core heat exchanger in which the O-ring is pressed into sealing engagement with the annular groove by means of a core retainer which is externally threaded to cooperate with an internal thread formed on the counterbore.
Another object of the present invention is the provision of a brass ring which encircles the tube retaining plate, the space between the tube retaining plate and the brass ring being filled with lead and the annular ledge being formed in the ring and solidified lead by cutting away an annular portion of the tube retaining plate, the solidified lead and the ring.
Another object of the present invention is the provision of a ledge and a shoulder, both of which are annular in configuration and which are coplanar.
The foregoing has outlined some of the more pertinent objects of the present invention. These objects should be construed to be merely illustrative of some of the more pertinent features and applications of the invention. Many other beneficial results can be attained by applying the disclosed invention in a different manner or modifying the invention within the scope of the disclosure. Particularly, with regard to the use of the invention described herein, this should not be construed to be limited to heat exchangers for oil coolers but should include heat exchangers for all engines, transmissions, hydraulic systems and the like.